Knob



FIG. 1 is a front, left side perspective view of a knob showing my new design;

FIG. 2 is a rear, right side perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a side elevational view thereof.

The broken lines in the drawing figures form no part of the claimed design. 

CLAIM The ornamental design for a knob, as shown and described. 